Definition
Air traffic control sectors that handle aircraft operating at or above flight level 240 (24,000 feet MSL), typically used by jets and turboprops on long-distance, high-altitude routes. Each sector is a defined block of airspace assigned to a specific controller responsible for traffic within it.
Plain English
Slices of upper-level airspace that ATC divides up so each controller can manage the high-flying jet traffic in their assigned area.
Context Anchor
Seen in discussions of en route instrument flying and how ATC divides airspace among controllers.
Derivation
Sector comes from a Latin word meaning “cutter” or “section.” That helps here because a sector is a cut-out section of airspace, not just a general area.
Why Pilots Care
Determines which frequency to monitor and which controller to expect handoffs from during high-altitude cruise.
Intuition Check
Do not read “sector” as just a wedge-shaped slice on a chart. In this context, it means a defined three-dimensional block of controlled airspace assigned to a controller.
Example Sentence 1
After climbing through FL240, the controller handed us off to the high altitude sector for the en route portion of the flight.
Example Sentence 2
Clearance for direct routing required coordination across three high altitude sectors.